LayerSlider update available for PHP 7.3?

I’m using Optimal with LayerSlider. In trying to update my site to the latest versions of PHP 7.x, I’m finding that LayerSlider works with 7.0, but not the higher versions. As 7.0 and 7.1 hit end of life in 2019, where can I get an update to LayerSlider that works with 7.3 to be current?

I saw a post on another site that said the LayerSlider is compatible with PHP 7.x in bundled themes, but not as a plugin (https://kriesi.at/support/topic/layerslider-wp-and-php-7-1/) Does that apply to Optimal?

Also, the LayerSlider page in WordPress has an Auto update available when a Purchase code is entered. If we purchased it through Appfinte with Optimal, is there a purchase code available?

Thanks.